Zebrafish synaptic proteome - Evolution of complexity in the zebrafish synapse proteome

The proteome of human brain synapses is highly complex and mutated in over 130 diseases. This complexity arose from two whole genome duplications early in the vertebrate lineage. Zebrafish are used in modelling human diseases, however its synapse proteome is uncharacterised and whether the teleost-specific genome duplication (TSGD) influenced complexity is unknown. We report the first characterisation of the proteomes and ultrastructure of central synapses in zebrafish and analyse the importance of the TSGD. The TSGD increased overall synapse proteome complexity. The Post Synaptic Density (PSD) proteome of zebrafish had lower complexity than mammals and a highly conserved set of ~1000 proteins is shared across vertebrates. PSD ultrastructural features were also conserved. Lineage-specific proteome differences indicate vertebrate species evolved distinct synapse types and functions. The datasets are a resource for a wide range of studies and have important implications for the use of zebrafish in modelling human synaptic diseases.